155156-87-9Relevant articles and documents
Efficient organocatalyst supported on a simple ionic liquid as a recoverable system for the asymmetric diels-alder reaction in the presence of water
De Nino, Antonio,Maiuolo, Loredana,Merino, Pedro,Nardi, Monica,Procopio, Antonio,Roca-Lpez, David,Russo, Beatrice,Algieri, Vincenzo
, p. 830 - 835 (2015)
The synthesis, characterization, and evaluation of a new highly efficient organocatalyst, namely, (5S)-2,2,3-trimethyl-5-thiobenzylmethyl-4-imidazolidinone hydrochloride, has been achieved. The catalyst possesses important structural features that should increase the catalytic efficiency and solubility in polar media. The application of the ionic-liquid-supported imidazolidinone catalyst in enantioselective Diels-Alder reactions was investigated. The Diels-Alder reactions of several dienes and dienophiles proceeded efficiently in the presence of the catalyst to provide the desired products in moderate to good yields and from good to excellent enantioselectivities. The conformation study confirms that in the transition state the Re face is shielded completely by the phenyl ring and an approach on the less hindered Si face is preferred. Particularly remarkable is the fact that the entire ionic liquid/HCl 0.01 M/catalyst system can be recovered and reused in up to six runs without an appreciable loss of catalytic activity. Confirming the conformation: The synthesis, characterization, and evaluation of a new highly efficient imidazolidinone organocatalyst is achieved. The catalyst is investigated in enantioselective Diels-Alder reactions, and a conformation study confirms the approach on the less hindered Si face. [mPy][OTf]=Methylpyridinium triflate.
Flow Chemistry-Enabled Divergent and Enantioselective Total Syntheses of Massarinolin A, Purpurolides B, D, E, 2,3-Deoxypurpurolide C, and Structural Revision of Massarinolin A
Cui, Chengsen,Dai, Mingji,Wang, Ye-Cheng
supporting information, p. 24828 - 24832 (2021/09/18)
Massarinolin A and purpurolides are bioactive bergamotane sesquiterpenes condensed with a variety of synthetically challenging ring systems: a bicyclo[3.1.1]heptane, an oxaspiro[3.4]octane, and a dioxaspiro[4.4]nonane (oxaspirolactone). Herein, we report the first enantioselective total syntheses of massarinolin A, purpurolides B, D, E, and 2,3-deoxypurpurolide C. Our synthesis and computational analysis also led to a structural revision of massarinolin A. The divergent approach features an enantioselective organocatalyzed Diels–Alder reaction to install the first stereogenic center in high ee, a scalable flow photochemical Wolff rearrangement to build the key bicyclo[3.1.1]heptane, a furan oxidative cyclization to form the oxaspirolactone, a late-stage allylic C?H oxidation, and a Myers’ NBSH-promoted sigmatropic elimination to install the exo methylene group of massarinolin A.
Synthesis of Main-Chain Ionic Polymers of Chiral Imidazolidinone Organocatalysts and Their Application to Asymmetric Diels–Alder Reactions
Haraguchi, Naoki,Takenaka, Nagisa,Najwa, Aisyah,Takahara, Yuta,Mun, Mah Kar,Itsuno, Shinichi
, p. 112 - 123 (2017/12/26)
Main-chain ionic polymers incorporating chiral imidazolidinone moieties in the polymer main chain were successfully synthesized by the polyaddition reaction of a chiral imidazolidinone dimer with a disulfonic acid. The organocatalytic activities of these polymers were investigated in the asymmetric Diels–Alder reaction between trans-cinnamaldehyde and 1,3-cyclopentadiene. The catalytic performance of the polymers was found to be sensitive to the chemical structure of the disulfonate units and the imidazolidinone dimer. With the use of these heterogeneous polymeric chiral organocatalysts, enantioselectivities of up to 99% for the endo isomer were obtained. This result was higher than those obtained with corresponding monomeric and dimeric counterparts in a homogeneous solution. The polymeric chiral organocatalyst was recovered and reused several times, maintaining its high enantioselectivity. (Figure presented.).
Enantioselective and collective syntheses of xanthanolides involving a controllable dyotropic rearrangement of cis-β-lactones
Ren, Weiwu,Bian, Yichao,Zhang, Ziyang,Shang, Hai,Zhang, Pengtao,Chen, Yuejie,Yang, Zhen,Luo, Tuoping,Tang, Yefeng
supporting information; experimental part, p. 6984 - 6988 (2012/09/25)
Let's swap: A scalable, atom-economic, enantio-, and diastereoselective synthetic route to trisubstituted γ-butyrolactones based on a Wagner-Meerwein-type dyotropic rearrangement of cis-β-lactones is described (see scheme). This methodology was applied in efficient and protecting-group-free formal syntheses and total syntheses of various xanthanolide natural products. Copyright
Highly enantioselective diels-alder reaction catalyzed by chiral imidazolidinone
Wang, Yongjiang,Xu, Xiaoliang,Pei, Wen
experimental part, p. 2032 - 2041 (2009/11/30)
New chiral imidazolidinone with an indole group was synthesized and used to catalyze the Diels-Alder reaction of α,β-unsaturated aldehyde with diene. High enantiomeric excesses and good yields were obtained. The reaction media were also surveyed. The best
Reusable montmorillonite-entrapped organocatalyst for asymmetric Diels-Alder reaction
Mitsudome, Takato,Nose, Kenta,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 5464 - 5466 (2008/12/22)
A chiral organocatalyst was successfully entrapped by montmorillonite clay using the cation-exchange method. The mont-entrapped organocatalyst acted as a highly efficient and reusable heterogeneous catalyst for the asymmetric Diels-Alder reaction, without loss of its initial activity.
A recyclable fluorous organocatalyst for Diels-Alder reactions
Chu, Qianli,Zhang, Wei,Curran, Dennis P.
, p. 9287 - 9290 (2007/10/03)
Chiral fluorous imidazolidinone catalyst 2 provides consistently high enantioselectivities in Diels-Alder reactions of dienes and α,β-unsaturated aldehydes. The catalyst can be readily separated from the reaction products by fluorous solid-phase extractio
Asymmetric Organocatalytic Diels-Alder Reactions on Solid Support
Selkaelae, Sami A.,Tois, Jan,Pihko, Petri M.,Koskinen, Ari M. P.
, p. 941 - 945 (2007/10/03)
Asymmetric organocatalysis on solid support combines the environmental advantages of metal-free catalysts and the ease of operation of solid-supported reagents. Enantioselective organo-catalytic Diels-Alder reactions have been demonstrated by two differen
Asymmetric Diels-Alder Reactions with α,β-Unsaturated Acetals
Sammakia, Tarek,Berliner, Martin A.
, p. 6890 - 6891 (2007/10/02)
Chiral α,β-unsaturated acetals derived from 2,4-pentanediol are shown to undergo Lewis acid promoted Diels-Alder reactions with good diastereoselectivity.
